OceanStor 6800T Customer expands LUN size in storage failed

During the process of using OceanStor S6800T, customer try to expand the size of one LUN which has been expanded in the system, the system reports the error and LUN expansion is failed.

Alarm Information

Alarm information：

Handling Process

According to the operation log, confirm that the customer is to use LunId 33(Dedupelun_3) to expand for LunId 9(DE02SASRG2LUN01):

To check the current state of LUN, LunId 9 is a primary LUN which has been expanded. And in this time of expansion, the slave LUN (LunId 33) is in the formatting state:

Though the slave LUN (LunId 33) is in the formatting state, but this is not the root for the failure of LUN extension. Exclude the reason about the status of LUN itself, continue to check whether it is configured any value-added feature:

Through ISM to find the corresponding LUN (LunId 9, DE02SASRG2LUN01), to select LUN advanced features > close SmartCache function. In the situation of not opening SmartCache, and then complete the LUN extension with the LUN (DE02SASRG2LUN01).

Root Cause

According to LUN information queried, to check the name of the LUN, ID, capacity, health status, running state, etc., in accordance with the restrictions in product documentation:

The situation about which primary LUN can’t be extended, as following:

The primary LUN (LunId 9) was added to SmartCache resource pool to open value-added feature SmartCache, this is the real root which causes LUN extension failed.

Solution

In the situation that the system doesn’t open any value-added features (such as SmartCache), and then complete the LUN extension.

Suggestions

According to the log, make sure whether LUN status meets the LUN extension requirements. The primary and slave LUN can’t be configured any value-added feature, before the implementation of LUN extension.